The present invention relates to an electric-motor-and-pump assembly including at least one bearing for the mounting support of a motor shaft in a motor housing, and a pump which is adapted to be attached to the motor and has at least one bearing for the mounting support of a pump shaft in a pump housing.
German application DE-OS 32 32 083 discloses a motor-and-pump assembly of this type. Torques are transmitted from the electric motor to the pump assembly by way of a pin shaped on a pump shaft end and engaging into a groove provided on the motor shaft end. The occurring torque is reliably transmitted by this arrangement, however, mounting of the assembly is complicated because the motor and pump can be installed only in a defined position of the shafts in relation to each other. Consequently, it is necessary to precisely maintain the assembly position and to make position checks. Manufacturing tolerances and a clearance provided to facilitate the assembly may provide a certain relief. It has shown, however, that a clearance between the shafts, both in radial and axial directions, produces undesirable noises during operation.
Therefore, an object of the present invention is to provide an electric-motor-and-pump assembly which offers ease of assembly and minimizes noises during operation.